Mufflers



J. P. MARX MUFFLERS Aug. 25, 1964' 2 Sheets-Sheet 1 Filed Jan. 23, 1961 INVENTOR. Jasqafi Ff A/A RX A Ornaz fl J. P. MARX 3,145,800

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United States Patent F 3,145,800 MUFFLERS Joseph P. Marx, 775 E. Summer St., Hartford, Wis. Filed Jan. 23, 1961, Ser. No. 84,125

2 Claims. (Cl. 181-45) The invention relates to improvements in silencers and is more particularly concerned with the novel construction and assembly of a mufiler of the replacement type embodying novel tone control means.

In view of the numerous makes of vehicles, the annual change in models and the wide range of variants in maximum back-pressure permissible and tone requisites, it is impractical for a service station to carry a replacement mufller embodying each of these requirements.

The improved mufller herein disclosed in an exemplary form embodies structural features adapting various parts thereof to be adjustably positioned relative to each other at the time of installation so as to alter the muffling or tone characteristics of the mufiier and, further, to facilitate adjustment of the back pressure characteristics of the muffler and the interchange of head and tail fittings thereof to adapt it for use in association with exhaust and tail pipes of different diameters.

It is therefore an object of the invention to provide a muflier structure having the foregoing advantages.

Another object is to provide a muffler structure which may be readily and efficiently assembled to meet specific installation requirements.

Another object is to provide a mufller construction embodying novel means to facilitate ready adjustment of the mufl ling or tone characteristics.

Another object is to provide a mufiler assembly com prised of interchangeable parts adapting the assembly to meet specific back pressure characteristics of a given vehicle in which it is to be installed.

Another object is to provide a rugged mufller assembly that is not expensive to construct, is easy to assemble, is capable of efficient sound control, provides maximum efficiency in silencing unwanted sound and is readily adaptable for installation in various types of vehicles.

Other and more detailed advantages and objects of the invention will appear more fully as the description proceeds, reference being made to the accompanying drawings wherein a preferred'form of the invention is shown. It should be understood however that the drawings and description are illustrative only and should not be taken as limiting the invention except insofar as it is limited by the claims.

In the drawings:

FIG. 1 is an elevational view of an exemplary muffler embodying the invention, showing a portion of the shell broken away.

FIG. 2 is an enlarged elevational view of the inlet end of the muffler, showing the inlet fitting flange and outer shell broken away in part.

FIG. 3 is an enlarged longitudinal sectional view of the exhaust end portion of the muffier. FIG. 4 is an enlarged longitudinal sectional view of the inlet end portion of the muffler. FIG. 5 is a transverse sectional view taken on line 5-- of FIG. 3.

FIG. 6 is a transverse sectional view taken on line 66 of FIG. 4.

3,145,800 Patented Aug. 25, 1964 Generally considered, the construction contemplates the assembly of mufflers in a manner to vary the mufliing characteristics and back pressure capacities and to adopt them for connection with exhaust and tail pipes of different diameters. The structure, when adjusted and assembled, constitutes an integral assembly. In the exem-. plary embodiment herein illustrated, the exhaust and inlet.

fittings are detachably connected to the muffler shell to facilitate the selection of fittings having diameters responding to the diameters of the usual exhaust and tail pipes of a given vehicle. Control of tone characteristics is obtained by the provision of a pair of novel telescoped conduits arranged within the muflier shell and which may be and assembly, the assembly adapts itself to use on vehicles spaced from the open end of hood 29, all for a purpose; to be explained presently. Also spaced substantially mid way between partitions 16 and 24 is a reinforcing ring 36 that is welded to the shell and has an axial opening of various types and models.

Referring now to the exemplary disclosure in the accompanying drawings, the muffler consists of an outer. shell 11, which preferably is oval in section but may be of any other functional shape, having end walls or headers 12, 13, one at each end thereof which preferably are. flanged on their outer perimeters, as at 12 and 13 respec-' tively, to permit the headers to be welded to the shell as shown. Each end wall is formed with an aligned axially located internally flanged opening 14, 15, respectively.

Referring now particularly to FIG. 3, a partition 01' baffle 16 is spaced inwardly from end Wall 13, within shell 11, to provide a collection chamber 17, and it has an external flange 18 secured, as by welding, to said shell.

This partition has an axially aligned flanged opening 19 through which one end of an outer tubular member 21, extends and to which said end is secured as by welding 22. The tubular member 21 extends axially through substantially the length of shell 11 but terminates short of endwall 12, it having its end telescoped in and secured, as by welding, within an axially aligned flanged opening 23 (FIG. 4) in a partition or baffle 24 that has its peripheral flange 25 Welded or otherwise secured firmly to shell 11. For purposes to be explained, presently, the baffles 16 and 24 are each provided with circumferentially spaced apertures 27, 28 respectively.

A cylindrical hood 29 is arranged around tubular member 21 and is spaced therefrom to provide a cylindrical chamber 31 which opens at one end adjacent'to baffle 16 and is closed at its other end by a reduced diameter 32 that is welded to tubular member 21, inwardly of partition 24. A deflector flange 33 (FIG. 3) is arranged closely adjacent to the open end of hood 29, and has an inner peripheral flange 34 welded to tubular member 21 and an outer peripheral flange 35 that overlies but is 37 larger than the external diameter of hood 29 so as to provide a circular passage surrounding said hood.

An inner tubular member 38 is extended through the flanged axial opening 14 in end wall 12 (FIG. 4) and is telescoped endwise snugly into the outer tubular member 21 and terminates substantially in the region of deflector flange 33 (FIG. 3), to define, with outer tubular member 21, a continuous conduit for the passage of exhaust gases and sound waves from the inlet end of the muffler to the collection chamber 17. A venturi element 39 is welded or otherwise secured to the open end of inner tubular member 38, the opening 41 therein being of any predetermined size required of the specific mufller installation.

As best shown in FIGS. 2 and 4, the mounted end of inner tubular member 38 has an external flange 42 that is seated against the outside face of end wall 12. This flange is provided with circumferentially arranged mutually spaced holes 43 which are adapted to align with threaded apertures in a like number of stake-nuts 44 carried by end wall 12. A similarly apertured Washer 45 is placed over said flange and a tubular inlet fitting 46 is then positioned thereover with its similarly apertured external flange 47 overlying the washer. The assembly is secured by screws 48 that are threaded into the stakenuts.

The end wall 13 also is provided with circumferentially arranged mutually spaced stake-nuts 49 to receive holding screws 51 that are passed through aligned apertures in a flange 52 of a tail pipe fitting 53 and an interposed washer 54.

The inlet and tail pipe fittings and the assembly just described are such that said fittings can be easily and quickly removed and fittings of other diameters can be attached to adapt the muffler assembly to receive exhaust and tail pipes of different diameters, which are, of course, secured thereto by any conventional clamp devices. The common detachable mounting of inlet fitting 46- and inner tubular member 38 serves the additional purpose of permitting easy and quick placement of an inner tubular member having a venturi element of any required size and, more important, affords means to facilitate circumferential adjustment of the inner tubular member with respect to the outer tubular member 21 for a purpose now to be described.

As best shown in FIGS. 3 and 5, inner tubular member 38 has circumferentially spaced longitudinally extending rows of mutually spaced holes 55, inwardly of the venturi end of said member. A second set of circumferentially spaced longitudinal rows of mutually spaced holes 56 also is provided in the inner tubular member (FIGS. 4 and 6), said rows preferably being in longitudinal alignment with the rows of holes 55, but spaced therefrom a short distance. In the present disclosure, there are four holes in each row of holes 55 and ten holes in each row of holes 56, but it should be understood that the number of holes in each of said rows and the number of rows of each may vary from the within description without detracting from the features of the invention.

When the inner tubular member 38 is in the position best illustrated in FIGS. 3, 4 and 6, the second set of holes 56 are in register with a like number of holes 57 in outer tubular member 21, while the first set of holes 55 are out of register with a complemental number of holes 58 in said outer tubular member. When the parts are in this relationship, the flow of exhaust gases and sound waves entering through inlet fitting 46 and flowing through conduit 21-38 is diverted in part through the registering openings 56, 57 and escapes into the circular chamber 31 defined by hood 29. The expanded gases and sound waves leaving chamber 31 flow around deflector flange 33 and are further expanded and turbulated as they enter the circular space between hood 29 and shell 11. The apertures 27, 28 in partitions 16, 24 respectively and apertures 59 in an auxiliary partition 61 arranged inwardly of end wall 12, permit free circulation and maximum turbulation of the escaped exhaust gases and sound 4 waves throughout the interior of shell 11 in a manner to diffuse the sound waves and muflle the exhaust noises.

The escaped turbulated gases and dampened sound waves entering the collection chamber 17 commingle with the direct exhaust flow through the conduit and pass out of the tail pipe fitting 53 and through the usual tail pipe (not shown) connected therewith. The flow of exhaust gases and sound waves through the large number of openings 56, 57 results in a larger proportion of the exhaust gases and sound waves escaping into shell 11 as compared with the volume flowing directly through the conduit with the result that the tone of exhaust is more subdued or softer.

In the event less muflling is desired, the inner tubular member 38 is rotated, in this instance, approximately so as to carry holes 55 in said inner tubular member into register with a like number of holes 58 in the outer tubular member. This effects full closing of holes 56, 57 and since the holes 55, 58 are fewer in number, the amount of exhaust gases and sound waves escaping into the interior of the shell is considerably lessened and a greater proportion of such gases and sound waves will flow straight through the conduit and into the tail pipe fitting with consequent increase in exhaust sound.

It should be understood that the number and size of the holes in the inner and outer tubular members is optional and that they can be increased or decreased in number and size to suit various installation requirements. It is preferred however, that the holes 57, 58 be larger than holes 55, 56 so as to avoid the necessity of absolute pre cision in their relative locations.

The present arrangement and disposition of the two sets of holes in the tubular members is preferable because it permits selective hole alignment by rotation of the inner tubular member 90 to effect a change in tone characteristics. Accordingly, there preferably are four equally spaced stake-nuts and registering holes at the mounting of the inner tubular member and end wall 12 so that upon removal of the screws, the inner tubular member can be rotated 90 and secured in its required position without requiring the drilling of new holes for the screws and without close examination of the mufller interior to ascertain the degree of circumferential adjustment attained. Of course, the stake-nuts can be dispensed with and conventional nuts used or the end walls may be tapped in the usual manner should such structures be preferred.

From the foregoing description it is believed that the nature of my invention and the manner in which it is to be carried out will be readily apparent to those skilled in this art.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A silencer having a conduit confined within an outer shell having end walls and forming a central passageway for exhaust gases and sound waves that extends from one end wall to adjacent the other end wall, an inlet in said one end wall in direct communication with one end of the conduit, a partition wall supporting the other end of said conduit and through which said conduit extends, said partition wall dividing the interior of the shell outside said conduit into an elongated expansion chamber and into a collection chamber, an exhaust fitting on said other end wall through which gases and sound waves entering the collection chamber are exhausted, said conduit comprising relatively adjustable parts telescoped one into the other endwise and each having apertures in their telescoped portions adapted to be selectively aligned to provide a pre-selected number of passages in the conduit Wall and through which a portion of the gases and sound Waves may escape, a cylindrical hood Within the expansion chamber surrounding at least the apertured area of said conduit, said hood opening at one end into the expansion chamber and defining an annular chamber into and through which said escaped gases and sound waves flow, and deflector means adjacent to the open end of said hood to reverse the direction of flow of said escaped gases and sound Waves leaving the annular chamber and entering the expansion chamber, said partition being apertured to permit the gases and sound waves in the expansion chamber to flow into the collection chamber.

2. The silencer recited in claim 1, in which baffies are arranged inthe expansion chamber to cause turbulation of the gases and sound waves in said chamber.

References Cited in the file of this patent UNITED STATES PATENTS Oldberg et al. Apr. 3, 1934 Hass et al July 26, 1938 Jensen et al. Nov. 5, 1940 Powers Sept. 5, 1944 Klemm Aug. 14, 1945 Billey June 14, 1960 

1. A SILENCER HAVING A CONDUIT CONFINED WITHIN AN OUTER SHELL HAVING END WALLS AND FORMING A CENTRAL PASSAGEWAY FOR EXHAUST GASES AND SOUND WAVES THAT EXTENDS FROM ONE END WALL TO ADJACENT THE OTHER END WALL, AN INLET IN SAID ONE END WALL IN DIRECT COMMUNICATION WITH ONE END OF THE CONDUIT, A PARTITIN WALL SUPPORTING THE OTHER END OF SAID CONDUIT AND THROUGH WHICH SAID CONDUIT EXTENDS, SAID PARTITION WALL DIVIDING THE INTERIOR OF THE SHELL OUTSIDE SAID CONDUIT INTO AN ELONGATED EXPANSION CHAMBER AND INTO A COLLECTION CHAMBER, AN EXHAUST FITTING ON SAID OTHER END WALL THROUGH WHICH GASES AND SOUND WAVES ENTERING THE COLLECTION CHAMBER ARE EXHAUSTED, SAID CONDUIT COMPRISING RELATIVELY ADJUSTABLE PARTS TELESCOPED ONE INTO THE OTHER ENDWISE AND EACH HAVING APERTURES IN THEIR TELESCOPED PORTIONS ADAPTED TO BE SELECTIVELY ALIGNED TO PROVIDE A PRE-SELECTED NUMBER OF PASSAGES IN THE CONDUIT WALL AND THROUGH WHICH A PORTION OF THE GASES AND SOUND WAVES MAY ESCAPE, A CYLINDRICAL HOOD WITHIN THE EXPANSION CHAMBER SURROUNDING AT LEAST THE APERTURED AREA OF SAID CONDUIT, SAID HOOD OPENING AT ONE END INTO THE EXPANSION CHAMBER AND DEFINING AN ANNULAR CHAMBER INTO AND THROUGH WHICH SAID ESCAPED GASES AND SOUND WAVES FLOW, AND DEFLECTOR MEANS ADJACENT TO THE OPEN END OF SAID HOOD TO REVERSE THE DIRECTION OF FLOW OF SAID ESCAPED GASES AND SOUND WAVES LEAVING THE ANNULAR CHAMBER AND ENTERING THE EXPANSION CHAMBER, SAID PARTITION BEING APERTURED TO PERMIT THE GASES AND SOUND WAVES IN THE EXPANSION CHAMBER TO FLOW INTO THE COLLECTION CHAMBER. 